1. Field of the Invention
The present invention relates to a container for a vessel whose height can be adjusted, and more particularly, to a variable height container for a vessel having mobile posts for adjusting the height thereof so that more freight can be easily shipped and the cost for carrying freight can be reduced.
2. Description of the Related Art
In general, a container for a vessel is a box used for containing freight and is manufactured according to the designated specifications so that it can be used in relation with various transportation methods. By using the container, shipping and discharging work can be mechanized, the cost for packaging can be reduced, and the possibility of theft can prevented. Also, as a number of containers can be piled up on a vessel, a large amount of freight can be transported at once on the sea.
There are many kinds of containers manufactured according to the type of freight such as a refrigerator container, a cold insulation container, a ventilation container, a bulk container, or a tank container in addition to a general dry container. In particular, to carry over-dimension freights such as steel, wood, or pipes and heavy freights such as machines, yachts, factory parts, or mechanical parts, a specially manufactured flat rack container is used. The flat rack container has the upper and lateral sides detached so that the weight of the containers piled up vertically is supported by only the four corner posts thereof.
An example of the conventional flat rack container is shown in FIG. 1. As shown in the drawing, the conventional flat rack container 110, in which the upper and lateral sides are detached, consists of a bottom plate 112 on which freight 1 is placed and four corner posts 114 vertically fixed at the four corners of the bottom plate 112.
Each of the four corner posts 114 has a corner cast 118 formed on the top end thereof. Here, through holes are formed in the upper surface and side surfaces of the corner cast 118 to be hooked by a hook of a spreader 2 which is a container moving apparatus. Thus, when the container is moved, the flat rack container 110 which is directly coupled to the spreader 2 through hooking is lifted and moved by a crane (not shown) at a wharf to be placed on a vessel.
However, when freight contained in the flat rack container 110 is so lengthy in the height than the height of the post of the flat rack container 110 so that the top end of the freight contacts the spreader. Thus, the corner cast 118 is hindered from being hooked by the spreader 2.
Accordingly, to carry the freight 1 placed in the conventional flat rack container 110, as shown in FIG. 1, a wire rope 7 having a hook 6 installed at the end thereof is used. The hook 6 is hooked into the holes of the corner cast 118 and the container 110 is moved from a vessel. Alternatively, the flat rack container 110 and the freight 1 are separately moved on a vessel and then the freight 1 is loaded in the container 110 on a vessel.
Hence, in the case of the conventional flat rack container 110, the cost for labor increases and the time for moving the freight is lengthened due to the above wire rope installation work or re-shipping process. Also, there is the possibility the freight in the container may fell out during movement thereof as the wire rope 7 sways and breaks due to the weight of the freight.
Also, as other containers cannot be loaded on and above the conventional flat rack container 110 loaded with high freight exceeding the height of the container as much as height OH, as shown in FIG. 2, the over-height container is restricted to be placed on top of the piled containers each having an identical specified container height H or on the bottom surface 4 of a vessel.
Therefore, according to the present transportation cost calculation method, a fee for the unused space S above the over-height container is unnecessarily included in the total cost. Also, as the space for such an over-height flat rack container is actually limited to the top portion of the piled containers, the conventional flat rack container 110 has to wait on the wharf until the appropriate space is prepared. Further, the number of containers to be transported are limited and the containers must be re-loaded at the next harbor.